Remote Control Equipment in Traffic Systems
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Questions and Answers

What is the primary purpose of a Remote Control Centre (RCC)?

  • To work in close liaison with traffic control. (correct)
  • To store electric traction equipment.
  • To monitor signal strength in remote areas.
  • To provide maintenance facilities for traction systems.

    • What type of equipment was primarily used before 1980 for Remote Control Centres?

  • Analog communication systems.
  • Frequency Modulated Voice Frequency Telegraph (FMVFT) equipment. (correct)
  • Supervisory Control And Data Acquisition (SCADA) systems.
  • Computer-based control systems.

    • What are the characteristics of the transmission path used in FMVFT equipment?

  • It uses wireless technology for signals.
  • It utilizes optical fiber for processing signals.
  • It consists of single core cables for better efficiency.
  • It employs star quads with an attenuation of about 0.3 dB/km. (correct)

    • What function do isolating transformers serve in the cable circuits?

    <p>To limit the longitudinal induced voltage.</p> Signup and view all the answers

    What is the purpose of the VF repeaters used in the FMVFT equipment?

    <p>To amplify the control signals to counteract line losses.</p> Signup and view all the answers

    How is the maximum gain of the repeater adjusted?

    <p>Based on the distance from the RCC or controlled post.</p> Signup and view all the answers

    What ratio do impedance matching transformers operate on in the communication setup?

    <p>1120:1120</p> Signup and view all the answers

    What is the maximum normal polling time for updating status in a system controlling 20 stations?

    <p>4 seconds</p> Signup and view all the answers

    What modulation technique do the modems utilize for communication between the master station and the RTUs?

    <p>Frequency Shift Keying (FSK)</p> Signup and view all the answers

    What is the primary function of the Mimic Diagram Board (MDB) in the SCADA system?

    <p>To provide an overall view of the traction power supply system</p> Signup and view all the answers

    What is the output signal level of the modems adjustable between?

    <p>0 and -30 dBm</p> Signup and view all the answers

    What additional feature of SCADA equipment allows control at boundary posts?

    <p>Interlock release request facility</p> Signup and view all the answers

    Which of the following annunciations is NOT indicated by a LED on the MDB?

    <p>Remote Station Defective</p> Signup and view all the answers

    What features does the SCADA software provide?

    <p>Multi-user, multi-tasking, net working and real time applications</p> Signup and view all the answers

    What is the required positioning for the RCC when controlling more than 30 stations?

    <p>In the middle of the electrified section</p> Signup and view all the answers

    How is historical data stored in the SCADA system?

    <p>For a period of one year</p> Signup and view all the answers

    What method does the master station use to communicate with RTUs?

    <p>Time Division Multiplexing</p> Signup and view all the answers

    Which of the following is a feature of the application software for the VDU displays?

    <p>Supports versatile semi-graphic colored displays</p> Signup and view all the answers

    What is the purpose of the parity check bits in the data exchange process?

    <p>To detect transmission errors</p> Signup and view all the answers

    Which component is phased out in the transition from conventional systems to SCADA?

    <p>Mimic Diagram Board</p> Signup and view all the answers

    What does the operator use to call any of the VDU displays?

    <p>Simple keyboard operation</p> Signup and view all the answers

    What type of systems does the SCADA system cater to?

    <p>Historical data on all alarms/events/measurands</p> Signup and view all the answers

    What is the primary purpose of the memory capacity provided for the feeder system?

    <p>To store feeder current and voltage data</p> Signup and view all the answers

    What happens in the event of a failure of one UPS in the Dual Stand-alone UPS System?

    <p>The healthy UPS takes over the entire load</p> Signup and view all the answers

    What is the purpose of storing changes in the status of CBS/interruptors in the RTU?

    <p>To eliminate loss in reporting due to failures</p> Signup and view all the answers

    Which statement accurately describes the battery capacity provided with the UPS?

    <p>It has adequate Ah capacity for 2 hours of supply during input failure</p> Signup and view all the answers

    Which type of modules are included in the Remote Terminal Unit (RTU)?

    <p>Digital input/output modules and alarm input modules</p> Signup and view all the answers

    How many controlled stations are designed for telecommands in a typical TSS system?

    <p>64</p> Signup and view all the answers

    What occurs if there is an outage of both UPS systems at the same time?

    <p>Load is directly connected to input mains through a static switch</p> Signup and view all the answers

    What is the maximum number of telesignals designed for a typical SP station?

    <p>12</p> Signup and view all the answers

    Which protective relays are tracked by the RTU in its operations?

    <p>OCR, DPR, and WPC</p> Signup and view all the answers

    What is the role of surge arresters in the RTU system?

    <p>To protect against voltage spikes</p> Signup and view all the answers

    What is the primary purpose of the isolating transformers in the SCADA system?

    <p>To limit induced voltage from 25 kV traction</p> Signup and view all the answers

    How frequently are voice frequency repeaters installed along the communication path?

    <p>Every 40-50 km</p> Signup and view all the answers

    What characterizes the transmission path between the Remote Terminal Units and the RCC?

    <p>Using underground telecommunication trunk cable</p> Signup and view all the answers

    What is the impedance ratio of the isolating transformers used in the SCADA system?

    <p>1120:1120</p> Signup and view all the answers

    What type of cable has been introduced for communication in some sections of Indian Railways?

    <p>Optical fiber cable</p> Signup and view all the answers

    What is the typical amplifier gain at the repeater stations in the SCADA system?

    <p>20 dB</p> Signup and view all the answers

    What is a critical feature of the switching station earthing in the SCADA system?

    <p>It is kept separate and distinct from other systems</p> Signup and view all the answers

    What is the function of the spare conductor pair within the underground trunk cable?

    <p>As a backup for failure conditions</p> Signup and view all the answers

    What frequency is used for the dedicated microwave channel provided in certain sections?

    <p>18 GHz</p> Signup and view all the answers

    What is the minimum gain provided by the amplifier in the modem to compensate for signal variation?

    <p>30 dB</p> Signup and view all the answers

    In terms of polling time, what is the maximum allowed when controlling 30 stations?

    <p>6 seconds</p> Signup and view all the answers

    Which of the following features allows automatic handling of faults in the SCADA system?

    <p>Automatic localization of fault</p> Signup and view all the answers

    At what input signal level does the modem function satisfactorily?

    <p>-45 dBm</p> Signup and view all the answers

    What is the maximum time for status update polling when controlling 20 stations?

    <p>4 seconds</p> Signup and view all the answers

    What technology has been predominantly adopted for Remote Control Centres after 1980?

    <p>Supervisory Control And Data Acquisition (SCADA)</p> Signup and view all the answers

    What is the attenuation rate of the underground cable circuits used in FMVFT equipment?

    <p>0.3 dB/km</p> Signup and view all the answers

    What does the isolating transformer limit in the cable circuits used by the FMVFT equipment?

    <p>Build up of longitudinal induced voltage</p> Signup and view all the answers

    What is the maximum gain that the VF repeaters can provide in the FMVFT equipment?

    <p>20 dB</p> Signup and view all the answers

    What distance intervals are isolating transformers provided in the underground cable circuits?

    <p>10 to 15 km</p> Signup and view all the answers

    What role do the impedance matching transformers play in FMVFT equipment?

    <p>To match communication cable impedance</p> Signup and view all the answers

    What type of equipment continues to operate in some Remote Control Centres despite being outdated?

    <p>Frequency Modulated Voice Frequency Telegraph (FMVFT)</p> Signup and view all the answers

    What is the main purpose of isolating transformers in the communication system?

    <p>To limit the build-up of longitudinal induced voltage</p> Signup and view all the answers

    What is the distance interval at which repeater stations are typically installed?

    <p>40-50 km</p> Signup and view all the answers

    Which of the following statements accurately describes the function of microwave communication on Indian Railways?

    <p>It uses a frequency of 18 GHz for dedicated communication</p> Signup and view all the answers

    What is the impedance ratio of the isolating transformers used in the SCADA system?

    <p>1120:1120</p> Signup and view all the answers

    What type of cable is used for transmitting signals from the RCC to the RTUs?

    <p>Underground telecommunication trunk cable</p> Signup and view all the answers

    What protective feature is implemented if the lead length for communication is long?

    <p>Surge arresters inside the equipment room</p> Signup and view all the answers

    What is the primary reason for keeping the switching station earthing separate from other earthing systems?

    <p>To prevent induction effects from 25 kV traction</p> Signup and view all the answers

    What type of communication system was introduced on Indian Railways in some sections apart from microwave channels?

    <p>Optical fiber communication</p> Signup and view all the answers

    What is the function of the spare conductor pair within the underground trunk cable?

    <p>For future expansions or additional connections</p> Signup and view all the answers

    What is the maximum capacity of the memory provided for the average feeder data storage?

    <p>40 MB</p> Signup and view all the answers

    In the case of a total UPS outage, how is the SCADA system powered?

    <p>Directly connected to input mains via a static switch</p> Signup and view all the answers

    What is the role of the watchdog transducers in the Remote Terminal Unit?

    <p>To oversee the operational status of connected devices</p> Signup and view all the answers

    What parameter indicates the maximum operational ability of the SCADA equipment at a typical TSS?

    <p>Number of controlled stations</p> Signup and view all the answers

    How does the RTU ensure that no event is lost before reporting to the master station?

    <p>By storing changes until the next polling</p> Signup and view all the answers

    Which components are directly connected to provide emergency power to various equipment during power failures?

    <p>Input mains through a static switch</p> Signup and view all the answers

    Which specific relays are monitored by the RTU in its operations?

    <p>Overcurrent, differential, and protective relays</p> Signup and view all the answers

    What is the designed capacity of telecommands for a typical SP station in the SCADA system?

    <p>12 telecommands</p> Signup and view all the answers

    What is one of the operational features of the Dual Stand-alone UPS System?

    <p>Load sharing is facilitated by synchronous operation of both UPS</p> Signup and view all the answers

    What happens to the battery connected to the UPS during power supply failure?

    <p>Maintains supply to essential SCADA components for 2 hours</p> Signup and view all the answers

    What ensures the automatic takeover of control in case of failure of one computer system at the master station?

    <p>The hot standby system</p> Signup and view all the answers

    Which feature allows the transfer of functions from one workstation to another in case of a complete outage?

    <p>Dual operator workstations</p> Signup and view all the answers

    What is the role of the mimic diagram board (MDB) at the Remote Control Centre?

    <p>To depict the status of traction power supply</p> Signup and view all the answers

    What type of storage is provided for the data logs within the master station equipment?

    <p>Hard and floppy disk drives</p> Signup and view all the answers

    How is the health of the master station computer systems monitored?

    <p>Watch dog timers</p> Signup and view all the answers

    What configuration allows for simultaneous operations at each workstation in the RCC?

    <p>Dual semi-graphic VDUs</p> Signup and view all the answers

    What functions do the functional keys on the RCC workstations serve?

    <p>Repeated operations for efficiency</p> Signup and view all the answers

    What is the purpose of having two data-logging printers connected to the same online computer system?

    <p>To allow redundancy in case one fails</p> Signup and view all the answers

    Which component controls the traffic information displayed to the operators at the RCC?

    <p>VDUs</p> Signup and view all the answers

    What is indicated by the mimic diagram board regarding the traction power supply?

    <p>Status of energize/de-energize conditions</p> Signup and view all the answers

    Study Notes

    Remote Control Equipment

    • Remote Control Centres (RCCs) are located near traffic control offices for electric traction divisions
    • RCCs consist of a main control room, equipment room, UPS room, remote control lab, and battery room
    • Types of equipment include Frequency Modulated Voice Frequency Telegraph (FMVFT), Supervisory Control and Data Acquisition (SCADA) systems
    • FMVFT equipment, a relay system, was prevalent before 1980, but is now outdated
    • SCADA equipment, using state-of-the-art technology, became popular after 1980
    • Transmission paths use underground cable circuits for voice frequency (VF) operation
    • Cable circuits have star quads with 0.3 dB/km attenuation, isolators every 10-15 km, VF repeaters every 30-50 km for signal amplification
    • Impedance matching transformers (1120:1120 ratio) are used at connection points to the RCC or controlled posts
    • Surge arresters protect circuits at cable termination points
    • Three pairs of conductors are used for telecommand signals (RCC to posts), telesignals (posts to RCC) and a spare pair
    • Control switching equipment includes pulse generator, send/receive selector circuits, check circuit, and indication circuit
    • Mimic diagram board in the RCC shows control points via discrepancy switches for remote control
    • Mimic diagram includes represented tracks, switches, and displays for various faults

    FMVFT Equipment

    • Control and indication signals are transmitted using 420-2460 Hz voice frequency channels (50 baud)
    • 18 channels are available, separated by 120 Hz
    • Frequency modulation is used, with transmitter modulating channel frequencies by ±30Hz
    • Transmission level has 22 dB loss over a 1120-ohm line
    • Receiving levels range from -22 dB to -30 dB
    • If more stations than 18 are controlled, redundant channel pairs are needed for telesignal purposes

    Controlled Post Equipment

    • Equipment is housed in one cabinet
    • Send and receive channel panels are used, the panels are plug-in type except the termination panel
    • Equipment operates on 24 V DC battery supply
    • Amplifier and attenuation pads are used for level adjustment

    SCADA Equipment

    • The master station for SCADA is located at the RCC
    • The controlled station equipment is the remote terminal unit (RTU)
    • Telecommunication trunk cable is used to transmit signals to RCC and RTUs
    • Communication cables contain three pairs: one for sending, one for receiving and one spare
    • Isolating transformers are placed every 10-15 km to prevent induced voltage
    • Cable taps in RCC and controlled stations terminate at a terminal board

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    Remote Control Equipment PDF

    Description

    Explore the essential components and technologies used in Remote Control Centres (RCCs) for electric traction divisions. This quiz covers the evolution of equipment like FMVFT and SCADA systems, as well as the technical specifications and protective measures in place for effective communication and operation.

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